The correct option is D x= 3, 7 2 Given, 2x^2 x=21 ⇒ 2x^2 x 21=0 ⇒ x = (1 ±√(1+168))4 = (1 ±√(169))4 = (1 ± 13)4 = 3 , 72 ...

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Roots of Quadratic Equation

Solve 2x2-x...

Question

Solve $2 x^{2} - x = 21$

x = - 2, \frac{3}{2}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

x = - 3, \frac{5}{2}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

x = - 1, \frac{3}{2}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

x = - 3, \frac{7}{2}

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D $x = - 3, \frac{7}{2}$
Given, $2 x^{2} - x = 21$
$\Rightarrow 2 x^{2} - x - 21 = 0$
$\Rightarrow x = \frac{(1 \pm \sqrt{1 + 168})}{4}$
$= \frac{(1 \pm \sqrt{169})}{4}$
$= \frac{(1 \pm 13)}{4}$
$= - 3, \frac{7}{2}$

Suggest Corrections

Similar questions

X = {1, 2, 3, 4, 5}, Y = {1, 3, 5, 7, 9},

X

Y

x

\frac{x - 2}{x - 3} + \frac{x - 4}{x - 5} = \frac{10}{3}; x \neq {3, 5}

lim x \to - 2 \frac{(\frac{1}{x} + \frac{1}{2})}{x + 2}

A = {y : y = {log}_{2} x, x < 16, x, y \in N}, B = {x : x^{2} - 7 x + 12 = 0}

(A \cup B) \times (A \cap B)

Factorise the following by splitting the middle term and find out the roots.
$2 x^{2} + x - 6 = 0$

Join BYJU'S Learning Program